I Q2 CORA JIPSON BECKWITH. 



EXPLANATION OF PLATE III. 

 Clava leptostyla. Figs. 15 to 19, X 350. 



FIG. 15. Same, showing reconstruction of daughter nuclei by chromosomal 

 vesicles. 



FIG. 1 6. Two-cell stage of Clava leptostyla passing into the four-cell 

 stage, second cleavage spindles showing. 



FIG. 17. Four-cell stage of Clava leptostyla with resting nuclei. 



FIG. 1 8. Four-cell stage of Clava passing into the eight-cell stage, spindles 

 showing in two cells. 



FIG. 19. Lateral view of eight-cell stage of Clava (five cells showing in 

 section), some of the cells with spindles, some with resting nuclei. 



